Peters



J. HUDSON.

(No Model.)

TUBE.

Patented June 9, 1885.

INVENTOR WITNESSES ATTORNEY N. PETERS. Pholwl-Nhognnher. Wishinglnn, D C

NITED STATE JAMES HUDSON, OF BIRMINGHAM, COUNTY OF WARWICK, ENGLAND.

TUBE.

SPECIFICATION forming part of Letters Patent No. 319,721, dated June 9, 1885.

Application filed September 8, 1884. (No model.) Patented in England January 14, 1884, No. 1,386.

T 0 all whom it may concern.-

Be it known that I, J AMES HUDSON, a subject of the Queen of Great Britain, residing at Birmingham, in the county of Warwick, England, have invented new and useful Improvements in Tubes, of which the following is a specification, and for which I have obtained a patent in Great Britain, No. 1,386, bearing date January 14, 1884.

My invention relates to an improved tube in two sections.

Hitherto tubes of this kind have usually been made either by soldering the edges of the outer. case or covering together, and afterward drawing it upon the tube to be covered through suitable dies, or by turning the edges into the open joint of the tube to be covered and looking it with another piece of metal, or by forming a groove (6. 0., by cutting or removing a part of the substance of the metal, thereby weakening the tube) in the tube to be covered, and so folding and locking the metal which forms the outer case or covering that when it is drawn through suitable dies the joint or folded part of the casing is forced into the said groove; but in method No. 2, above described, it is found in practice that a regular and good joint cannot be produced by reason of the springing open of the tube after passing the dies, and much waste of material often occurs, while in both of the methods (2 and 3) it has been found in practice that a perfect lock-joint is not obtainable.

By my improved method a good sound joint is produced, and the loss from waste is reduced to a minimum.

I firstprovide a strip of iron or base metal, which, by drawing through suitable dies, I form into a tube having an open joint, and on the opposite side to this open joint is simultaneously formed a deep recess or indentation, extending below the line of the inner side of the tube. This recess or indentation is by preference nearly V-shaped. I next prepare, by drawing through suitable or chilled dies, the Strip of brass or other metal which is to form the casing or cover, with its two edges turned inward, as is now commonly the practice in the manufacture of stair-rods, as referred to in the British patent of \Veston, No. 3,315, 1869. This covering is then passed over the first-mentioned tube of iron or base metal. The tubes are then drawn together through suitable or chilleddies, and may be reduced in size to any desired degree. The effect of this last-mentioned process is to close the V-shaped groove upon the inward-turned edge of the outer casing, and so securely hold them therein.

Inasmuch as the tendency of the V to spring open is reduced to a minimum, a much more perfect joint can by means of my invention be obtained than by either of the processes before referred to.

' It will be understood that in some cases, and more particularly in the construction of largersized tubes, it is sometimes desirable to form the iron or base metal tube by means of suitable rolls.

That my invention may be better understood, I have annexed drawings thereof,which I will now proceed to describe.

Figure 1 is a transverse section of the iron or base metal inner tube, a, in its first stage of bending, the open joint being at a and the recess or indentation being a, this being often not made to its full depth by the first die or set of rolls through which it passes. Fig. 2 is a partial elevation of the foregoing tube. Fig. 3 is a transverse section of the iron or base metal tube a after it has passed through the die, dies, or rolls which bring the edges together at the open joint, and which give the proper depth to the groove, recess, or indentation a It will be observed that the inner part of this recess is below-that is, more nearly approaches the center of the tube than the general surface of the inside of the tube. Fig. 4 is a partial elevation of the tube in the same stage of manufacture as Fig. 3. Fig. 5 is a transverse section through the outer tube or casing, b, of brass or some other fine metal. This is formed, as is the inner tube, a, from a strip of metal, by drawing through a die or dies, or passing through rolls. The edges 1) b are, it will be seen, bent up so as to fit into 7 is a transverse section through the finishedcased tube, which now has had its correct shape IOO given to it, and has had its size reduced, if piece of metal with edges bent to be c0ntigu- I5 desired. It will be seen that the sides of the ous to each other and provided with a jaw in V -shaped groove a are now forcibly eomits wall removed from said edges and having pressed together, and they grip and hold pera continuous surface projecting inwardly, as

5 fectly fast the inward bent edges of the outer shown, in combination with an outer tube havcasing. Fig. 8 is a partial longitudinal secing its edges clamped within the jaw of the 20 tion through the finished-cased tube. inner tube, substantially as set forth. The sanie letters of reference indicate the same parts in. each of the figures. JAMES HUD 10 Having now particularly described my in- Witnesses:

vention, what I claim is I SAML. F. G. WHITAKER,

The within-described improved tube in two Guns. W. H. J OHNSTONE,

sections, consisting of an inner tube and an Clerks to T. Emery Davies, Solicitor, Birmingouter tube, the inner tube formed of a single ham. 

